1. Field of the Invention
The present invention relates to an impact absorbing member for a vehicle and, in particular, to an impact absorbing member for a vehicle that is suitably used in order to absorb the impact generated when the knees of an occupant of the vehicle are involved in a secondary collision with, for example, an instrument panel.
2. Description of the Related Art
An impact absorbing member for a vehicle made of a synthetic resin in which a foamed layer is formed within a hard skin layer is known in, for example, Japanese Patent Application Laid-open No. 11-60769. This impact absorbing member for a vehicle comprises a hard skin layer formed by cooling and solidifying that portion of a foamable thermoplastic synthetic resin in contact with a mold device it has been injected into and a foamed layer formed within the skin layer by moving a part of the mold so as to foam an unhardened synthetic resin within the skin layer.
With regard to the above-mentioned conventional arrangement, the foamed layer is made to have a large thickness in order to enhance the impact absorbing effect, it takes a correspondingly long time to mold and it cannot be said that the productivity is high.
The present invention has been carried out in view of the above-mentioned circumstances, and it is an object of the present invention to provide an impact absorbing member for a vehicle that can improve the productivity.
In order to achieve the above-mentioned object, in accordance with a first aspect of the present invention, there is proposed an impact absorbing member for a vehicle, comprising a plurality of synthetic resin foams arranged in a stack, the foams being formed from a hard skin layer and a foamed layer formed within the skin layer.
In accordance with the above-mentioned arrangement, since the impact absorbing member for a vehicle comprises the plurality of foams arranged in a stack, the foamed layer of each of the foams can be relatively thin, the time required for molding each of the foams using a mold can be relatively short and the productivity of manufacture of the impact absorbing member for a vehicle can be improved.
Furthermore, in accordance with a second aspect of the present invention, in addition to the above-mentioned first aspect, there is proposed an impact absorbing member wherein irregular sections that mate with each other are formed on superimposed surfaces of the plurality of foams. In accordance with the above-mentioned arrangement, when the impact absorbing member receives an impact, the mating of the irregular sections can prevent the plurality of foams from slipping relative to each other. Moreover, the stress applied to the impact absorbing member can be dispersed by the irregular sections that mate with each other, and the impact absorbing ability can be further enhanced in comparison with a foam merely having an increased thickness.
Furthermore, in accordance with a third aspect of the present invention, in addition to the above-mentioned first aspect or second aspect, there is proposed an impact absorbing member wherein a void is formed between the superimposed surfaces of the plurality of foams. In accordance with the above-mentioned arrangement, the impact absorbing ability of the impact absorbing member can be yet further enhanced by the air layer of the void.
The above-mentioned objects, other objects, characteristics and advantages of the present invention will become apparent from an explanation of preferred embodiments that will be described in detail below by reference to the attached drawings.